CVE-2026-91860: Vaadin Charts and Component Base prototype pollution in deep merge

CVE-2026-91860 · Severity: info · Published 2026-09-30

Vaadin Charts and Vaadin Component Base contain a prototype pollution vulnerability in their deep merge helper functions. When untrusted data is merged into chart configurations or component i18n properties, it can modify Object.prototype, allowing injected properties to affect all objects in the running application. This could lead to application-wide behavior changes or security bypasses depending on how the affected properties are used.

Technologies: Vaadin. Vendors: Vaadin.

Quick answers

Is CVE-2026-91860 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-91860 being exploited in the wild.
How severe is CVE-2026-91860?
Informational severity, published 30 September 2026.
Which products and versions are affected?
Vaadin Charts 23.0.0-23.6.4, 24.0.0-24.9.17, 24.10.0-24.10.4, 25.0.0-25.1.11, 25.2.0-25.2.8; Vaadin Component Base 24.7.0-24.9.17, 24.10.0-24.10.4, 25.0.0-25.1.11, 25.2.0-25.2.8; Vaadin 23.0.0-23.6.13, 24.0.0-24.9.20, 24.10.0-24.10.9, 25.0.0-25.1.11, 25.2.0-25.2.6; Vaadin Charts Flow 23.0.0-23.6.13, 24.0.0-24.9.20, 24.10.0-24.10.9, 25.0.0-25.1.11, 25.2.0-25.2.6; and 1 more.
Is there a fix for CVE-2026-91860?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-91860 attacked?
It is attacked over the network.
Am I affected by CVE-2026-91860?
Check whether you run Vaadin Charts, Vaadin Component Base, Vaadin or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability is a prototype pollution flaw in deep merge helpers used by Vaadin Charts and Vaadin Component Base. When an application merges untrusted data into chart configuration or i18n properties without proper validation, the merge operation writes to Object.prototype instead of staying confined to the target object. An attacker can inject properties that become visible to every object in the application, potentially enabling logic bypasses or privilege escalation depending on how those properties are consumed.

Affected products

  • Vaadin Vaadin 23.0.0-23.6.13, 24.0.0-24.9.20, 24.10.0-24.10.9, 25.0.0-25.1.11, 25.2.0-25.2.6
  • Vaadin Vaadin Core 24.7.0-24.9.20, 24.10.0-24.10.9, 25.0.0-25.1.11, 25.2.0-25.2.6
  • Vaadin Vaadin Charts Flow 23.0.0-23.6.13, 24.0.0-24.9.20, 24.10.0-24.10.9, 25.0.0-25.1.11, 25.2.0-25.2.6
  • Vaadin Charts 23.0.0-23.6.4, 24.0.0-24.9.17, 24.10.0-24.10.4, 25.0.0-25.1.11, 25.2.0-25.2.8
  • Vaadin Component Base 24.7.0-24.9.17, 24.10.0-24.10.4, 25.0.0-25.1.11, 25.2.0-25.2.8

Timeline

  • 2026-09-30: disclosed

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